竖向压力条件对黄土抗剪强度的影响规律  

Laws of Shear Strength of Loess Influenced by Vertical Pressure

作　　者：邱明明 王弘起 孙杰龙 郑隆君 田宇轩 QIU Mingming;WANG Hongqi;SUN Jielong;ZHENG Longjun;TIAN Yuxuan(School of Architectural Engineering,Yan’an University,Yan’an 716000,China;SCEGC No13 Construction Engineering Group Company Ltd,Yan’an 716099,China)

机构地区：[1]延安大学建筑工程学院,陕西延安716000 [2]陕西建工第十三建设集团有限公司,陕西延安716099

出　　处：《土木工程与管理学报》2023年第2期37-43,共7页Journal of Civil Engineering and Management

基　　金：陕西省重点研发计划资助项目(2020ZDLSF06-03);陕西省教育厅服务地方专项计划项目(21JC035);延安市重点研发计划项目(2019ZCSY-006);延安大学科研计划资助项目(CXY202006,YDY2020-36,YDZ2019-08)。

摘　　要：明确黄土物理力学性质是分析黄土地质体稳定性的重要依据。以延安新区原状与重塑黄土为研究对象,采用改进的室内直剪试验方法对原状与重塑黄土高、低压力条件下的抗剪强度进行测试,研究不同湿度、密度和高、低压力条件下原状与重塑黄土抗剪强度及抗剪强度指标的变化规律。研究结果表明:低压力、低含水率条件下黄土试样剪应力-剪切位移关系曲线具有明显的“单峰”特征,高压力条件下黄土试样剪应力-剪切位移关系曲线呈持续增长趋势,无明显峰值特征;原状黄土强度指标明显大于重塑黄土,且湿度和密度变化对黏聚力的影响程度较内摩擦角更显著;高、低压力段下的黄土抗剪强度指标存在显著差异,建议在对黄土边坡浅层稳定性分析时按照包含低压力条件下的直剪试验获取抗剪强度指标值。Clarifying the physical and mechanical properties of loess is an important basis for analyzing the stability of loess geological body.The undisturbed and remolded loess in Yan’an new District were selected as the research object.The shear strength of undisturbed and remolded loess under high and low pressure were measured by the improved laboratory direct shear test method,and the change rule of shear strength and shear strength indexes of undisturbed and remolded loess under different moisture,density and high and low pressure were studied.The results show that the shear stress-shear displacement curve of loess under the conditions of low pressure and low moisture has an obvious“single peak”characteristic,and the shear stress-shear displacement curve of loess increases continuously without obvious peak characteristic under high pressure condition.The strength index of undisturbed loess is significantly larger than that of remolded loess,and the influence of moisture and density on cohesion is more significant than that of internal friction angle.There are significant differences between the shear strength indexes of loess under high and low pressure segment,so it is suggested that the shear strength index should be obtained according to the direct shear test under the condition of containing low pressure when analyzing the shallow stability of loess slope.

关 键 词：黄土 竖向压力 抗剪强度 黏聚力 内摩擦角 

分 类 号：TU444[建筑科学—岩土工程]